Across
- 2. Organism with a new or improved characteristic.
- 5. Reuse wast
- 7. An area of salt water covering most of the Earth
- 8. An organised collection of living and non-living elements in a natural environment.
Down
- 1. Degradation of a natural environment by toxic substances or waste.
- 2. Gas essential for breathing
- 3. Oxygen-free zone where people die of asphyxiation
- 4. Cultivate the land.
- 6. Polymeric materials